Android 4.0.3 issue: "Back" button disappears

Android 4.0.3 issue: "Back" button disappears

This issue happens most on HTC devices with Android 4.0.3 platform.

I have created an easy app by using jQuerry mobile 1.3.0 with 3 simple pages (1), (2), (3) and "Back" button on it. To surf that pages I'm using  this function:

<a class="ui-link-inherit" href="#" onclick="changePage('index1.php')" data-transition="slide">Example 1</a>

function changePage(page) {
    $.mobile.changePage(page, { changeHash:true});
}

So, when I open that pages one-by-one and get to the last page (3), then I click "Back" button and second page (2) appears. But the "Back" button on the second page (2) disappeared and I can't move to the first page (1).

As example, providing You a link on my app, so You can check that:
http://testmobile.polar-b.com/

Please, help me to resolve this issue.

Thanks!